1. Technical Field
The present invention relates to a technology of displaying an image by controlling a liquid crystal alignment.
2. Related Art
A vertical alignment (VA)-mode liquid crystal panel was conventionally suggested in that molecules of a liquid crystal are aligned along with the vertical direction against a substrate when no voltage is applied to a liquid crystal (the non-voltage state.) JA11-52361 (a paragraph 0012) is an example of the related art. This type of a liquid crystal can improve the contrast ratio of an image, being preferable for a projection apparatus (a projector) in which a high contrast ratio is required.
Here, in this vertical alignment (VA)-mode liquid crystal panel, it is preferable to perfectly align liquid crystal molecules against a substrate at the time of the non-voltage state, only viewing from the improvement of the contrast ratio. When liquid crystal molecules are vertically aligned against a substrate, however, it become difficult to quantitatively control a behavior of each of molecules, in particular, the direction of changing the alignment, after voltage is applied to them. This difficulty results in a problem of yielding the discrenation caused by derangement of the alignment of molecules.
In order to overcome the problem, it was considered that liquid crystal molecules are aligned toward a direction, which is slightly tilted from the direction vertical toward a substrate at the time of a the non-voltage state. However, in this alignment, the remarkable birefringence of a liquid crystal at the non-voltage state may offset an advantage of the high contrast ratio of the VA mode.